Automotive grade 3-phase MOSFET pre-driver IC for brushless DC motor control

July 26, 2011 // By Christoph Hammerschmidt
Allegro MicroSystems Europe's new A4933 is an automotive-grade 3-phase MOSFET pre-driver IC for the control of brushless DC motors in applications such as electronic power steering systems, engine cooling fans, transmission actuators and hydraulic pumps.

The device is primarily targeted at extreme applications where high power, high torque and high temperature combine to require a MOSFET pre-driver that is able to deliver large MOSFET gate drive and switching capabilities. It is particularly suited to use in 3-phase systems - especially those which use sinusoidal control of the motor phase currents.

This commutation method provides smooth operation, which reduces audible noise and minimises torque ripple at the load.

Key features of the A4933 include an integrated charge pump that provides full gate drive for battery voltages down to 7 V and reduced gate drive for battery voltages as low as 5.5 V; a top-off charge pump that enables 100% pulse-width modulation; an adjustable dead time that can be regulated by the user; an adjustable drain-to-source monitor; and improved fault diagnostics that enhances the user's ability to decode and identify faults.

The A4933KJPTR-T is available in a 48L eLQFP small-profile thermally efficient package with exposed pad.

A copy of the data sheet can be obtained here: http://www.allegromicro.com/en/Products/Part_Numbers/4933/4933.pdf